154 VOLUME 11, NUMBER 5, OCTOBER 2002
relation and calibration. Journal of Experimental Scheck, B., Neufeld, P., & Dwyer, J. (2000). Actual
Wells, G.L., Malpass, R.S., Lindsay,
Psychology: Applied, 8, 44 56. innocence. New York: Random House.
R.C.L., Fisher, R.P., Turtle, J.W., &
Shaw, J.S., III. (1996). Increases in eyewitness con-
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Fulero, S. (2000). From the lab to fidence resulting from postevent questioning.
tional Center for Health Statistics. (n.d.). Na-
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the police station: A successful ap-
tional Health and Nutrition Examination Survey.
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American Psychologist, 55, 581 598.
datatblelink.htm#unpubtab postevent questioning can lead to elevated lev-
els of eyewitness confidence. Law and Human
Dunning, D., & Perretta, S. (in press). Automatic-
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Sporer, S., Penrod, S., Read, D., & Cutler, B.L.
ond rule for distinguishing accurate from
(1995). Choosing, confidence, and accuracy: A
Note
inaccurate positive identifications. Journal of
meta-analysis of the confidence-accuracy rela-
Applied Psychology.
tion in eyewitness identification studies. Psy-
1. Address correspondence to Gary
Illinois Commission on Capital Punishment. (2002,
chological Bulletin, 118, 315 327.
L. Wells, Psychology Department, April). Report of the Governor s Commission on
Technical Working Group for Eyewitness Evi-
Capital Punishment. Retrieved April 23, 2002,
Iowa State University, Ames, IA 50011; dence. (1999). Eyewitness evidence: A guide for
from http://www.idoc.state.il.us/ccp/ccp/
law enforcement. Washington, DC: U.S. Depart-
e-mail: [e-mail].
reports/commission_report/
ment of Justice, Office of Justice Programs.
Juslin, P., Olson, N., & Winman, A. (1996). Calibra- Wells, G.L., & Bradfield, A.L. (1999). Distortions in
tion and diagnosticity of confidence in eyewit- eyewitnesses recollections: Can the postiden-
ness identification: Comments on what can tification-feedback effect be moderated? Psy-
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Read, J.D., Vokey, J.R., & Hammersley, R. (1990).
and identification accuracy. Journal of Applied
Changing photos of faces: Effects of exposure Wells, G.L., Small, M., Penrod, S., Malpass, R.S.,
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Brewer, N., Keast, A., & Rishworth, A. (2002). Im- and the accuracy-confidence relationship. Eyewitness identification procedures: Recom-
proving the confidence-accuracy relation in Journal of Experimental Psychology: Learning, mendations for lineups and photospreads. Law
eyewitness identification: Evidence from cor- Memory, and Cognition, 16, 870 882. and Human Behavior, 22, 603 647.
if they form a single ornament
Evolutionary Psychology of
that signals mate quality.
Facial Attractiveness
Moreover, some researchers
have recently explained attrac-
Bernhard Fink1 and Ian Penton-Voak
tiveness preferences in terms
Ludwig-Boltzmann-Institute for Urban Ethology, Vienna, Austria (B.F.),
of individual differences that
and Department of Psychology, University of Stirling, Stirling, Scotland,
are predictable. This article
United Kingdom (I.P.-V.)
briefly describes what is cur-
rently known from attractive-
ness research, reviews some
recent advances, and suggests
areas for future researchers at-
Abstract studying the relationships be-
tention.
The human face communi- tween attractiveness and (a)
cates an impressive number of symmetry, (b) averageness,
Keywords
visual signals. Although and (c) nonaverage sexually di-
face; attractiveness; mate choice;
adults ratings of facial attrac- morphic features (hormone
evolutionary psychology
tiveness are consistent across markers). Evolutionary psy-
studies, even cross-culturally, chology proposes that these
there has been considerable characteristics all pertain to
An obsession with beauty is not
controversy surrounding at- health, suggesting that humans
unique to modern Western culture
tempts to identify the facial have evolved to view certain
but can be found around the world
features that cause faces to be features as attractive because
in almost all societies that have
judged attractive or unattrac- they were displayed by healthy
been studied. Several studies have
tive. Studies of physical attrac- individuals. However, the
shown that members of different
tiveness have attempted to question remains how single
ethnic groups share common attrac-
identify the features that con- features that are considered at-
tiveness standards, suggesting that
tribute to attractiveness by tractive relate to each other, and
the constituents of beauty are neither
Published by Blackwell Publishing Inc.
CURRENT DIRECTIONS IN PSYCHOLOGICAL SCIENCE 155
arbitrary nor culture bound. Beauty metry can be associated with at- prototypical exemplars, and that
and sexual attractiveness seem to be tractiveness for reasons other than their attraction to average faces is a
almost interchangeable concepts, and direct effects of symmetry per se. reflection of this more general pro-
people of different social classes, Scheib, Gangestad, and Thornhill pensity. Exactly what features con-
ages, and sexes tend to rate human (1999) found a relationship be- tribute to the preference for aver-
faces similarly. Evolutionary psy- tween women s attractiveness rat- ageness, and whether these effects
chologists have suggested that ings of faces and symmetry even represent an adaptation or by-
such a ubiquitous phenomenon as when symmetry cues were re- products of other adaptations, re-
beauty may reflect human psycho- moved by presenting only the left mains unclear.
logical adaptations and mate pref- or right half of each face. These re-
erences. Certainly, the high consen- sults suggest that attractive fea-
sus of people s judgments of facial tures other than symmetry can be
HORMONE MARKERS
attractiveness is consistent with the used to assess physical condition.
theory of biologically based stan- Symmetry may simply covary with
dards of beauty. Evolutionary psy- these other features rather than act- In many species, including hu-
chology has focused on the percep- ing as a primary cue to attractive- mans, testosterone production and
tion of three major cues that may ness. Other researchers have of- metabolism mobilizes resources to
underpin biologically significant fered an alternative account of the encourage males to attract and
assessments of mate value: (a) symmetry-attractiveness link, ar- compete for mates. Testosterone af-
symmetry, (b) averageness, and (c) guing that symmetry is more fects a number of facial features. In
nonaverage sexually dimorphic readily perceived by the visual sys- pubertal males, a high testoster-
features. tem than other perceptual cues are. one-to-estrogen ratio facilitates the
Consequently, it may be the case lateral growth of the cheekbones,
that the human preference for fa- mandibles, and chin; the forward
cial symmetry is not the result of growth of the bones of the eyebrow
SYMMETRY
evolved psychological adaptations, ridges; and the lengthening of the
but rather is a by-product of the lower facial bone. Because testos-
Bilateral symmetry of physical perceptual system s design. terone suppresses the immune sys-
traits is hypothesized to reflect an tem, such  masculine traits may
overall high quality of develop- represent an honest signal of qual-
ment, especially the ability to resist ity, as the individual with high tes-
environmental perturbations dur- tosterone has successfully coped
AVERAGENESS
ing development. Hence, a sym- with its somewhat debilitating ef-
metrical face may signal the ability fects.
of an individual to cope with the Preference for average traits in Hormone markers are also
challenges of his or her environ- some facial features could have present in females. The signaling
ment. Symmetry of bilateral traits evolved because in many heritable value of many female body fea-
is positively correlated with ge- traits, the average denotes het- tures is linked to age and repro-
netic heterozygosity (i.e., the pres- erozygosity. Studies indicate that ductive condition, both of which
ence of different variants of a gene computer-generated average faces correspond to a woman s ratio of
on homologous chromosomes) in are rated as more attractive than al- estrogen to testosterone. Attractive
many animals, including humans, most all of the individual faces features (e.g., prominent cheek-
and may signal an outbred mate or they are constructed from. It has bones) correspond to high ratios
provide information on an individ- been known for some time, how- and signal fertility, but estrogen in
ual s genetic diversity in defense ever, that average faces can be women could be a handicapping
against parasites. Numerous stud- made more attractive by manipu- sex hormone as testosterone is in
ies have demonstrated that assess- lating specific features to make men. Thus, markers of high estro-
ments of attractiveness are sensi- them nonaverage. In a recent gen may reliably signal that a fe-
tive to facial symmetry. Preferences study, however, Halberstadt and male s immune system is of such
for symmetric faces may thus have Rhodes (2000) found a strong rela- high quality that it can deal with
some adaptive value. tionship between averageness and the toxic effects of high estrogen.
Despite several studies demon- attractiveness also for nonface ob- In this context, skin condition is
strating the direct effects of sym- jects like drawings of dogs, birds, presumed to reliably signal aspects
metry on rated attractiveness, and watches. It may be that hu- of female mate value. Human
other research suggests that sym- mans have a general attraction to males, universally, are expected to
Copyright © 2002 American Psychological Society
156 VOLUME 11, NUMBER 5, OCTOBER 2002
be most sexually attracted by fe- the attractiveness of men s faces. suggests that the neural mecha-
male skin that is free of lesions, Varying female preferences may nism responsible for generating
eruptions, warts, moles, cysts, tu- reflect alternative tactics in a condi- positive feelings toward male faces
mors, acne, and hirsutism. The ab- tional mating strategy that trades is sensitive to levels of hormones
sence or presence of body hair is a off cues to supposedly good genes circulating in the blood.
sexually dimorphic characteristic, against other factors, such as socia-
and relative hairlessness and bility.
smooth skin in women may signal
fertility because of its association
INDIVIDUAL DIFFERENCES
with low androgen and high estro-
IN PERCEPTIONS
gen. Skin infection may denote a
ATTRACTIVENESS AND THE OF ATTRACTIVENESS
disturbance of the production of
MENSTRUAL CYCLE
androgen and estrogen and re-
duced reproductive ability. Empir- Clearly, individual differences
ical evidence shows that women s The menstrual phase has been in attractiveness judgments exist,
facial skin texture affects males shown to influence females percep- as not all people find exactly the
judgments of their facial attractive- tion of male attractiveness. Specifi- same faces attractive. Recently,
ness, and homogeneous (smooth) cally, females exhibit a shift in pref- however, studies have indicated
skin is most attractive (Fink, Gram- erence toward a more masculine that certain psychological factors
mer, & Thornhill, 2001). Males male face during the phase of their influence preferences in a predict-
evaluate females skin texture in menstrual cycle when likelihood of able way. Johnston et al. (2001)
addition to the characteristics of conception is high (Johnston, Hagel, compared women who scored low
age and facial shape in judging fa- Franklin, Fink, & Grammer, 2001; on a psychological  masculinity
cial beauty. Penton-Voak et al., 1999). Trends in test with those who received
The link between hormone the data indicate that this shift may higher scores and found that the
markers and attractiveness in male be influenced by a woman s relation- low scorers showed a larger prefer-
faces is, however, complex. Al- ship status (i.e., women show larger ence shift across the menstrual cy-
though some studies support the shifts toward masculinity when cle, had lower self-esteem, and had
hypothesis that women prefer mas- judging attractiveness in the context a greater preference for male facial
culinized male faces, other studies of a potential short-term relationship dominance cues in potential short-
indicate that women do not have than in the context of a potential long- term mates. Johnston et al. supposed
clear preferences for such traits in term relationship). Furthermore, wo- that father-daughter bonding could
males. Perrett et al. (1998) showed men in relationships tend to show enhance a female s self-esteem and
that females preferences regarding larger cyclic shifts than women who reduce her sensitivity to male dom-
male faces are apparently driven are not in relationships. inance cues, whereas a lack of at-
by stereotypical personality attri- These shifts in preferences have tachment could have the reverse
butions: Highly masculinized male been interpreted as representing effect. Additional evidence for ex-
faces were perceived as less warm, adaptive trade-offs in mate choice. periential influences on attractive-
less honest, and more dominant than Females choose a relatively feminine ness judgments comes from a re-
feminized male faces. Such attribu- face (possibly indicating prosociality, cent study (Perrett et al., 2002)
tions may have a kernel of truth, as or acting in ways that tend to bene- demonstrating that, in adulthood,
high testosterone has been linked fit other people without the prospect the offspring of older parents were
with antisocial behavior in men. of an external personal benefit, and less impressed by youth in a poten-
However, the variability in willingness to invest in offspring) tial partner than were the children
women s preferences for hormone when they are unlikely to conceive, of younger parents.
markers seems to represent some yet may prefer more masculine Moreover, in a study compar-
of the best evidence for evolved ad- faces when sex is likely to result in ing females who did and did not
aptations in the facial attractive- pregnancy (so that they may gain consider themselves to be physi-
ness literature. The studies demon- heritable benefits). Taken together, cally attractive, those who consid-
strating this variability fall into two these studies provide strong evi- ered themselves physically attrac-
categories, those investigating the dence for a hormone-mediated tive showed a greater preference
influence of menstrual-cycle phase adaptive design. A female s attrac- for two proposed markers of qual-
on women s preferences in male tion to testosterone markers on a ity in male faces: masculinity and
faces and those investigating indi- male s face may be influenced by her symmetry (Little, Burt, Penton-
vidual differences in perceptions of estrogen/progesterone ratio. This Voak, & Perrett, 2001). This finding
Published by Blackwell Publishing Inc.
CURRENT DIRECTIONS IN PSYCHOLOGICAL SCIENCE 157
can be interpreted in terms of a The redundant-signal hypothe- and receiver of the contact. In an
conditional strategy, as this in- sis also suggests that there are mul- experiment in which participants
creased preference for masculine tiple features, each signaling a dif- viewed faces varying in attractive-
faces was seen only when judg- ferent aspect of mate quality, but ness and direction of eye gaze,
ments were made in the context of adds that these features are consid- Kampe, Frith, Dolan, and Frith
a long-term relationship. Poten- ered against one another in arriv- (2001) showed that brain activity in
tially, women with high mate ing at an evaluation. That is, ac- the ventral striatum (a brain area
value may be able to elicit different cording to this hypothesis, mate associated with prediction of re-
behaviors from masculine-looking choosers pay attention to several ward) reflected an interaction of
men than women with lower mate sexual ornaments in combination the two variables. Specifically,
value. Recently, a similar varying to obtain a better estimate of gen- when eye gaze was directed toward
preference for masculinity has eral condition than if they paid at- the viewers, activity in the ventral
been found using women s facial tention to any single ornament. In a striatum increased as attractive-
attractiveness and waist-to-hip ra- recent study, Grammer, Fink, ness increased, and when eye gaze
tio, rather than self-rated attrac- Juette, Ronzal, and Thornhill (2001) was directed away from the view-
tiveness, as the putative measures showed that this hypothesis is bet- ers, activity in this area decreased
of female viability. ter than the multiple-message hy- as attractiveness increased. Thus,
pothesis for explaining how signals depending on the direction of gaze,
actually contribute to female at- perceived attractiveness can acti-
tractiveness, although its validity vate brain regions that are strongly
for the assessment of male attrac- linked to reward, and eye contact
BEAUTY: A SINGLE
tiveness remains to be investi- with attractive individuals ap-
ORNAMENT OF
gated. Support for the redundant- pears to be more  rewarding than
MATE QUALITY?
signal hypothesis also comes from eye contact with less attractive in-
Thornhill and Grammer (1999). dividuals.
Symmetry, averageness, and They asked participants to judge This finding has been confirmed
hormone markers probably have the attractiveness of the same by Aharon et al. (2001), who
interacting effects on the percep- women in each of three poses (face, showed that discrete categories of
tion of attractiveness. The question front nude with face covered, and beautiful faces have differing re-
of how these features relate to one back nude) and found a significant ward values and differentially acti-
another, then, is important. Re- positive correlation between the vate reward circuitry in human
search has focused mainly on the ratings for the three poses in both subjects. Functional magnetic reso-
analysis of single features and their Austrian and U.S. participants. Be- nance imaging shows that passive
contribution to attractiveness, but cause the attractiveness features of viewing of beautiful female faces
this approach may be inherently the face, back, and front are all re- activates the brain s reward cir-
limited, as attractiveness may not lated to estrogen, the correlation of cuitry, but studies in which the at-
be reducible to the analysis of a sin- the ratings of the different pictures tractiveness of male faces was
gle feature. The ecological litera- implies that women s faces and rated indicate that aesthetic evalua-
ture suggests two alternative ex- bodies form what amounts to a sin- tion may be separate from reward
planations of how features relate to gle ornament of honest mate value. assessment.
one another: the multiple-message
hypothesis and the redundant-signal
hypothesis (MÅ‚ller & Pomianowski,
BEAUTY HAS A
1993). According to the former,
REWARD VALUE CONCLUSION
each ornament signals a specific,
unique property of the condition of
an individual. This hypothesis cor- Another influential component If we accept that evolutionary
responds to the multiple-fitness of attractiveness is eye gaze, as eye processes have shaped our psycho-
model of Cunningham, Roberts, contact is an important part of logical adaptations, it seems likely
Wu, Barbee, and Druen (1995), social interaction. Gaze provides that human beings evolved mecha-
which states that perceived attrac- different levels of meaning (e.g., nisms for detecting and assessing
tiveness varies across multiple di- social attention or even  mind cues of mate value. Furthermore,
mensions, rather than a single di- reading through eye gaze) de- these mechanisms are presumed to
mension, with each feature signaling pending on the status, disposition, be highly resistant to cultural mod-
a different aspect of mate value. and emotional state of the sender ification, although many cultural
Copyright © 2002 American Psychological Society
158 VOLUME 11, NUMBER 5, OCTOBER 2002
Grammer, K., Fink, B., Juette, A., Ronzal, G., &
markers of attractiveness (e.g., beauty is only  skin deep or rather
Thornhill, R. (2001). Female faces and bodies:
body decoration) clearly contribute lies in the adaptation of the be-
N-dimensional feature space and attractive-
ness. In G. Rhodes & L. Zebrowitz (Eds.),
to interpersonal attraction. Re- holder.
Advances in visual cognition: Vol. 1. Facial attrac-
cently, research has indicated that
tiveness Evolutionary, cognitive, cultural and
motivational perspectives (pp. 97 125). Westport,
cues to attractiveness are inte-
Recommended Reading
CT: Ablex.
grated to form a single ornament of
Halberstadt, J., & Rhodes, G. (2000). The attrac-
Rhodes, G., & Zebrowitz, L. (Eds.).
mate value. The slightest introspec- tiveness of non-face averages: Implications for
(2001). Advances in visual cognition: an evolutionary explanation of the attractive-
tion, however, informs us that indi-
ness of average faces. Psychological Science, 11,
Vol. 1. Facial attractiveness Evolu-
viduals differ in their judgments of 285 289.
tionary, cognitive, cultural and moti-
Johnston, V.S., Hagel, R., Franklin, M., Fink, B., &
attractiveness. Such individual dif-
vational perspectives. Westport, CT:
Grammer, K. (2001). Male facial attractiveness:
Ablex.
ferences may reflect the operation
Evidence for hormone mediated adaptive de-
Thornhill, R., & Gangestad, S.W. sign. Evolution and Human Behavior, 22, 251
of adaptive conditional mating
267.
(1999). Facial attractiveness.
strategies that trade off cues to ge-
Kampe, K.K., Frith, C.D., Dolan, R.J., & Frith, U.
Trends in Cognitive Sciences, 3, 452
netic and direct benefits, as well as (2001). Reward value of attractiveness and
460.
gaze. Nature, 413, 589.
individual differences in experi-
Little, A.C., Burt, D.M., Penton-Voak, I.S., & Per-
ence across the life span.
rett, D.I. (2001). Self-perceived attractiveness
influences human preferences for sexual di-
Despite the general consensus
morphism and symmetry in male faces. Pro-
Note
among evolutionary psychologists
ceedings of the Royal Society of London B, 268,
39 44.
that facial attractiveness reflects
1. Address correspondence to Bern-
MÅ‚ller, A.P., & Pomianowski, A. (1993). Why have
adaptations that discriminate the
hard Fink, Ludwig-Boltzmann-Insti-
birds got multiple sexual ornaments? Behav-
tute for Urban Ethology, Althanstrasse ioral Ecology and Sociobiology, 32, 167 176.
mate value of individuals, there are
14, A-1090 Vienna, Austria; e-mail: Penton-Voak, I.S., Perrett, D.I., Castles, D.L., Koba-
still open questions that remain to
yashi, T., Burt, D.M., Murray, L.K., & Mina-
[e-mail].
be solved. Future research should
misawa, R. (1999). Female preference for male
faces changes cyclically. Nature, 399, 741 742.
direct further attention to how
Perrett, D.I., Lee, K.J., Penton-Voak, I., Rowland,
variations in life history affect at-
D., Yoshikawa, S., Burt, D.M., Henzi, S.P., Cas-
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Published by Blackwell Publishing Inc.